Various processes for the catalytic hydrogenolysis of chlorofluorocarbons and hydrochlorofluorocarbons are known. For example, U.S. Pat. No. 2,942,036 discloses the reaction of 1,2,2-trichloropentafluoropropane with hydrogen in the presence of palladium on activated carbon catalyst to produce 1,2,2-trihydropentafluoropropane. The examples show that under the conditions of the experiments one of the products from this reaction is CF.sub.3 CH.dbd.CF.sub.2. The carbon support may be treated with aqueous HF prior to depositing palladium on the support for the purpose of removing silica from the carbon. U.S. Pat. No. 5,315,048 discloses a process wherein 1,2,3-trichloropentafluoropropane is contacted with hydrogen in the presence of palladium on alumina to produce 1,1,1,2,3-pentafluoropropane. It is mentioned in this patent that reduction of 1,2,3-trichloropentafluoropropane with hydrogen over Pd on carbon gives primarily a mixture of HCF.sub.2 CHFCF.sub.2 H and HCF.sub.2 CHFCF.sub.2 Cl. U.S. Pat. No. 4,319,060 discloses a process wherein 1,1-dichlorotetrafluoroethane contained in mixtures thereof with 1,2-dichlorotetrafluoroethane is selectively degraded to provide 1,2-dichlorotetrafluoroethane substantially free of 1,1-dichlorotetrafluoroethane. The process includes contacting, in the vapor phase, an organic feed composition containing a major amount of the 1,2-isomer and a minor amount of the 1,1-isomer with hydrogen in the presence of a hydrodechlorination catalyst. C. Gervasutti et al., J. Fluorine Chem., 19, 1-20 (1981/2) report that 1,1,1,2-tetrafluoroethane was prepared from isomeric mixtures of dichlorotetrafluoroethanes through selective hydrogenolysis of the CF.sub.3 CCl.sub.2 F isomer present in the mixture catalyzed by Pd/C. The other isomer CClF.sub.2 CClF.sub.2 appeared more stable to hydrogenolysis and was only converted partially to the monohydrogenated derivative CHF.sub.2 CClF.sub.2.
U.S. Pat. No. 5,136,113 discloses catalytic hydrogenolysis of fluorohalocarbons and fluorohalohydrocarbons using catalysts of certain metals (e.g., palladium) on low-ash carbon. Various other processes using catalysts containing acid-washed carbon have been studied. A. A. Goleva et al., Russ. J. Phys. Chem., 442, 290-1 (1970) discloses the dehydrochlorination of 1,1,2,2-tetrachloroethane to the olefin trichloroethylene (and HCl) using activated charcoal as the catalyst. Activated charcoal treated with hydrochloric acid proved to be more active than an untreated specimen for the production of trichloroethylene.